Internet Connection Sharing

From NixOS Wiki
Revision as of 11:27, 17 April 2023 by imported>Onny

The following example will describe how to share an active internet connection over a WiFi hotspot or alternatively via ethernet.

Share via WiFi

Usage

Share an existing internet connection of a wired interface eth0 using a wifi hotspot on wlan0 with the access point name MyAccessPoint.

nix shell nixpkgs#linux-wifi-hotspot
sudo create_ap wlan0 eth0 MyAccessPoint

Configuration

Persistent share an existing internet connection of a wired interface eth0 using a wifi hotspot on wlan0 with the access point name My Wifi Hotspot. The network is protected with a simple WPA2 pre-shared key 12345678.

services.create_ap = {
  enable = true;
  settings = {
    INTERNET_IFACE = "eth0";
    WIFI_IFACE = "wlan0";
    SSID = "My Wifi Hotspot";
    PASSPHRASE = "12345678";
  };
};

Share via ethernet

Share an existing internet connection of a wireless interface wlan0 to clients connected on a ethernet device eth0.

# Setup ethernet device
ip link set up eth0
ip addr add 10.0.0.1/24 dev eth0

# Enable packet forwarding
sysctl net.ipv4.ip_forward=1

# Enable NAT for leaving packets
iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE

# Start dnsmasq for DHCP
dnsmasq -d -i eth0 -F $client,$client,1m -O option:dns-server,1.1.1.1,1.0.0.1 &
# Cleanup
ip addr del $host dev $link
ip link set down $link
iptables -t nat -D POSTROUTING -o $wanlink -j MASQUERADE
iptables -D DOCKER-USER -i $link -j ACCEPT
iptables -D DOCKER-USER -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT